Especially in the fields of cytobiology and medicine sample chambers having integrated conductor paths and electrodes are used for the testing of cells, specifically living cells. Among others, the alternating current resistance of an electrode covered with cells is measured as a function of time. Such sample chambers are also referred to as MEA (Multi Electrode Array) systems. Also, it is possible to use MEA systems for chemical and pharmacological applications.
A MEA system is known, for example, from U.S. Pat. No. 5,187,096 which comprises several receiving wells for receiving the cells to be tested, in which electrodes are arranged for measuring the impedance of cell cultures. The electrodes are connected to contact strips which are, again, connected to leads leading out of the MEA system. In order to supply power or connect the contact strips to measuring devices the leads are connected to external equipment.
Another MEA system combined with a holder is known from U.S. Pat. No. 5,563,067. The apparatus comprises a device for receiving cells, which is arranged on a carrier and on the bottom of which a planar electrode with a plurality of microelectrodes is arranged. Again, conductors are led out of the device for receiving the cells. These conductors are arranged on the upper surface of the carrier and comprise several electrical contact points for the connection to a power supply or for connecting the conductors to measuring devices.
In any one of these systems electrical contact points serve to establish an electrically conductive connection to conductors in the MEA system. Again, measuring electrodes inside a device for receiving cells are connected to the conductors. An external voltage source or a suitable measuring device can be connected to the contact points, specifically by means of contact elements on the holder of the MEA system.
All of the prior systems have in common that the contact points project over the device for receiving cells of the MEA system. Especially in systems where the conductors and electrodes are formed of very thin layers or are arranged on thin carrier plates it may occur that the contact points or the conductors connecting same to the electrodes in the MEA system are easily damaged.